Water infiltration through walls or other building structures composed of building blocks can be costly, damaging, and dangerous. Erosion, which can be caused by water and/or other elements, can accelerate water infiltration and cause structural instability. Water that infiltrates into a building through the building blocks and/or the building structure can create an excessively humid internal environment, and the excessive humidity can cause further problems, such as, but not limited to, mold growth. Health risks have been increasingly associated with many molds.
Building blocks of various sizes, shapes, and materials have been used in the construction of various structures. Some of the materials have included stone, brick, concrete, cinder, and tile. Many of these materials form a solid and sturdy, but somewhat porous block, with surfaces that are generally rough, or at least not substantially smooth. Regardless of the particular type or shape of the building block, each building block in a construction application is laid adjacent to another structure (e.g., another building block), usually spaced by a bed of mortar. The mortar can at least partially fill the joint between a building block and the adjacent structure.
A single wythe construction method is a relatively inexpensive method in which blocks are stacked in rows to create a structure (e.g., a wall) with the width of a single block. In a below-ground, single wythe application, where ground exists on one side of the building block structure, and open space exists on the other side of the building block structure, ground water can create a pressure greater on one side of the building block structure, forcing water against, into, and/or through the building block structure. In an above-ground, single wythe application, where one side of the building block structure is exposed to an external environment and the weather, and the other side of the building block structure is exposed to internal environment protected from the weather, wind creates a pressure difference between the two sides of the building block structure that also forces water against, into, and/or through the building block structure, from the side exposed to the wind toward the side protected from the wind.
Water forced against, into, and/or through the building block structure can work its way through the pores in the actual block, but more prevalently, the water flows through cracks, voids, and gaps in the mortar joints. Cracks in the mortar joint can also result from a variety of causes, such as shifts in the building block structure, degradation of the mortar or block materials, or erosion caused by water and/or other elements. Gaps and voids in the mortar joint can result from a variety of causes also, such as, but not limited to, human imperfection or error during installation of the mortar, or erosion caused by water and/or other elements. For example, water inside a crack that freezes and expands can enlarge the crack.
Some methods attempting to prevent water penetration that involve a single wythe construction include spraying the weather-exposed side of the building block structure with a sealant spray, such as a polyurethane spray, installing a flashing to help drain water away from the building block structure, or fashioning drainage grooves within the building blocks and the building block structure. Unfortunately, these methods have been insufficiently effective. Spray sealants are inefficient, as they do not effectively seal where new cracks form after application of the spray sealant. Drains are inefficient because portions of mortar fall into the drains often when a mason installs the building blocks and mortar, thereby clogging the drains. Screens can be installed to catch the mortar in an attempt to reduce the amount of mortar that clogs the drains, but this installation requires extra work, and masons frequently, or usually, overlook these extra laborious procedures.
Another method that attempts to prevent water penetration involves building two single wythe structures separated by an air gap that serves as a drainage gap. Drainage holes can be built to extend through the width of the exterior structure exposed to weather. The drainage holes can be spaced along the bottom of the structure, so that water that penetrates into or through the exterior structure can drain into the drainage gap and then out of the building structure through the drainage holes. This double wythe method requires more materials, labor, and expense.
It would be desirable to provide a building block that can be used to overcome the disadvantages discussed above.
It would be desirable to provide a building block that can be used to create a single wythe building block structure that, compared to current building block structures, relatively inexpensively and effectively reduces or prevents water penetration through mortar joints.